Configure Automatic Migration from Your Database

After you create a database connection in the Dashboard, you enable user migration from that database and create custom scripts to determine how the migration happens.

These custom scripts are Node.js code that run in the tenant's sandbox. Auth0 provides templates for most common databases, such as: ASP.NET Membership Provider, MongoDB, MySQL, Oracle, PostgreSQL, SQLServer, Windows Azure SQL Database, and for a web service accessed by Basic Auth.

Navigate to Auth0 Dashboard > Authentication > Database, and select the database to view.
Select the Custom Database view, and enable the Use my own database switch.
Select the Settings view, enable the Import Users to Auth0 switch, and select Save.

To see the scripts you need to configure:

Select the Custom Database view, and locate Database Action Scripts.

Dashboard - Authentication - Database - Custom Database - Database Action Scripts

Login: Executes each time a user who is not found in the Auth0 database attempts to log in. Verifies that the user exists in the legacy database without re-prompting the user for their password.
Get User: Executes following any of these actions:
- a user attempts to sign up
- a user clicks on valid password change confirmation link
- the Management API receives a call to the Update a User's Email or Username endpoint

If a user who has not been migrated confirms a password change, their user profile will be created in Auth0 with the new password. This user profile will contain all the information returned in the Get User script. All subsequent logins for this user will be performed directly in Auth0. You may see unexpected behavior if you return differing user profiles in the login and get_user scripts.

After you've enabled migration, you can verify the users that have migrated by doing one or both of the following tasks:

Use the List or search users Management API endpoint.
Navigate to Auth0 Dashboard > User Management > Users, and review the list of users.

Once all your users are in the Auth0 database, you are ready to convert the database so that it uses only users stored in Auth0.

Navigate to Auth0 Dashboard > Authentication > Database, and select the database to view.
Select the Custom Database view, locate Database Action Scripts, and update the Login script:
function login (email, password, callback) { return callback(null, null); }
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Also update the Get User script:

function getByEmail (email, callback) {
  return callback(null, null);
}

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By doing this, you are changing the Login and Get User Database Action Scripts to NO-OP functions, which essentially makes your database connection behave as a non-custom database connection.

Make sure to leave the Import Users to Auth0 option turned on. If you turn this option off Auth0 will only use the scripts to authenticate and perform other user actions instead of using the users that were imported locally.

After you have verified the migration, you can disconnect your legacy database (not the Auth0 database). If you modified the scripts as instructed above, Auth0 will not try to connect to your legacy database.
Keep Import Users to Auth0 (in the Settings view) enabled. This, combined with the NO-OP script changes, will ensure that only the Auth0 users database is used.
Configure rules to execute other functions when a user authenticates to your application.

The most common error message that you may encounter when importing users from a legacy database to an Auth0 custom database is "The user already exists."

When a user is imported, a partial user state is first created on the Auth0 end to make this migration possible. If you delete this user from the Auth0 connection then later recreate the user, you may receive this error. In addition, the Get User script is called on user creation. If you attempt to create a new user in the Auth0 custom database connection and the user already exists in your external database, you will receive this error.

If you encounter a "user already exists" error message, use the Management API's endpoint to delete a connection user to delete the user. Confirm that the user does not exist in your legacy database, then recreate the user.

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